The individual tubes are mostly manufactured from metal or from any other material, wherein individual plain bearings are fixed as guiding and/or sliding system, thereto. One side of the plain bearing slides along a surface of the next largest or next smaller tube. For counteracting torsional forces, some of the conventional tubes have recesses or rails, guiding the plain bearings mounted to the other tube. A distance between the tubes and the plain bearings may be adjusted by washers or flat washers. The adjustment is often performed by a screw and/or an inclined surface. In some conventional lifting pillars, plain bearings are replaced by roller bearings.
Due to the arrangements described, the plain bearings and the slide and/or guiding system of conventional lifting pillars may have a comparatively large dimension. Thereby, a gap between two tubes may become comparatively large. In some lifting pillars, an effort for selecting a plain bearing with the required thickness or for shimming it accordingly, may also be increased due to the fact that a plurality of plain bearings are part of a sliding system. For example, three plain bearings may be provided for round tubes, and tubes with a rectangular cross-section may be provided with four plain bearings, thus one on each side, or even eight plain bearings, thus two at each corner. Often, a number of plain bearings may additionally duplicate, since the plain bearings may be inserted at both ends of the tubes.